Merge "docs: Updates to API Overview for N Preview 2" into mnc-mr-docs

        <li><a href="#doze_on_the_go">Doze on the go</a></li>

        <li><a href="#background_optimizations">Background optimizations</a></li>

        <li><a href="#data_saver">Data Saver</a></li>

        <li><a href="#vulkan">Vulkan API</a></li>

        <li><a href="#tile_api">Quick Settings Tile API</a></li>

        <li><a href="#number-blocking">Number-blocking</a></li>

        <li><a href="#call_screening">Call screening</a></li>

        <li><a href="#apk_signature_v2">APK signature scheme v2</a></li>

        <li><a href="#scoped_directory_access">Scoped directory access</a></li>

        <li><a href="#launcher_shortcuts">Launcher shortcuts</a></li>

        <li><a href="#print_svc">Print service enhancements</a></li>

      </ol>

</div>

</div>

Saver and make an effort to limit foreground and background data usage.</p>

<h2 id="vulkan">Vulkan API</h2>

<p>

  Android N integrates <a href="http://www.khronos.org/vulkan" class=

  "external-link">Vulkan™</a>, a new 3D rendering API, into the platform. Like

  <a href="https://www.khronos.org/opengles/" class="external-link">OpenGL™

  ES</a>, Vulkan is an open standard for 3D graphics and rendering maintained

  by the Khronos Group.

</p>

<p>

  Vulkan is designed from the ground up to minimize CPU overhead in the driver,

  and allow your application to control GPU operation more directly. Vulkan

  also enables better parallelization by allowing multiple threads to perform

  work such as command buffer construction at once.

</p>

<p>

  Vulkan development tools and libraries are rolled into the Android NDK. They

  include:

</p>

<ul>

  <li>Headers

  </li>

  <li>Validation layers (debug libraries)

  </li>

  <li>SPIR-V shader compiler

  </li>

  <li>SPIR-V runtime shader compilation library

  </li>

</ul>

<p>

  Vulkan is only available to apps on devices with Vulkan-capable hardware,

  such as Nexus 5X, Nexus 6P, and Nexus Player. We're working closely with our

  partners to bring Vulkan to more devices as soon as possible.

</p>

<p>

  For more information, see the <!-- TODO: Insert link to blog post -->Vulkan

  Developer Tools blog post or the <a href=

  "{@docRoot}ndk/guides/graphics/index.html">API documentation</a> itself.

</p>

<h2 id="tile_api">Quick Settings Tile API</h2>

<h3 id="work_profile_security_challenge">Work profile security challenge </h3>

<p>

  Profile owners can specify a separate security challenge for apps running in

  Profile owners targeting the N SDK

  can specify a separate security challenge for apps running in

  the work profile. The work challenge is shown when a user attempts to open

  any work apps. Successful completion of the security challenge unlocks the

  work profile and decrypts it if necessary. For profile owners,

</p>

<p>

  Profile owners can set distinct password policies for the work challenge

  Profile owners can set distinct passcode policies for the work challenge

  (such as how long the PIN needs to be, or whether a fingerprint can be used

  to unlock the profile) using the <code>setPasswordQuality()</code>,

  <code>setPasswordMinimumLength()</code> and related methods. The profile

  <strong>Settings&gt;More&gt;Vpn</strong>.

</p>

<h3 id="custom_provisioning">Customized provisioning</h3>

<p>

  An application can customize the profile owner and device owner provisioning

  flows with corporate colors and logos.

  <code>DevicePolicyManager.EXTRA_PROVISIONING_MAIN_COLOR</code> customizes

  flow color. <code>DevicePolicyManager.EXTRA_PROVISIONING_LOGO_URI</code>

  customizes the flow with a corporate logo.

</p>

<h2 id="accessibility_enhancements">Accessibility enhancements</h2>

<p>Android N now offers Vision Settings directly on the Welcome screen for new

<pre class="no-pretty-print">

$ adb shell dumpsys shortcut

</pre>

<p>

  To update all shortcuts and to delete dynamic shortcuts, use the appropriate

  methods that the Launcher Shortcut API provides. For more details about this

  API, see <code>android.content.pm.ShortcutManager</code> in the downloadable

  <a href="{@docRoot}preview/setup-sdk.html#docs-dl">API Reference</a>.

</p>

<h2 id="print_svc">Print Service Enhancements</h2>

<p>

  In Android N, print service developers can now surface additional information

  about individual printers and print jobs.

</p>

<p>

  When listing individual printers, a print service can now set per-printer

  icons in two ways:

</p>

<ul>

  <li>You can set an icon from a resource ID by calling

  <code>PrinterInfo.Builder.setResourceIconId()</code>

  </li>

  <li>You can show an icon from the network by calling

  <code>PrinterInfo.Builder.setHasCustomPrinterIcon()</code>, and setting a

  callback for when the icon is requested using

  <code>android.printservice.PrinterDiscoverySession.onRequestCustomPrinterIcon()</code>

  </li>

</ul>

<p>

  In addition, you can provide a per-printer activity to display additional

  information by calling <code>PrinterInfo.Builder.setInfoIntent()</code>.

</p>

<p>

  You can indicate the progress and status of print jobs in the print job

  notification by calling

  <code>android.printservice.PrintJob.setProgress()</code> and

  <code>android.printservice.PrintJob.setStatus()</code>, respectively.

</p>

<p>

  For more information about these methods, see the downloadable <a href=

  "{@docRoot}preview/setup-sdk.html#docs-dl">API Reference</a>.

</p>